Isn't it the duty of miners to include maximum txs in blocks?
If blocks aren't full and txs are blocked, Btc seems as less attractive and reliable.
Hence investors will be less numerous and people will tend to use other altcoins.
Hence price will not rise as much.
I feel like I'm missing a really important point cause my reasoning is really too simple xD
The important point is that nobody is compelled to do anything, by anything other than their own best interests. The whole ecosystem relies on it. If any part of the ecosystem relies on the few then it is doomed to fail the same way as every other centrally planned system has, or will fail, due to "best intentions".
When a block is found it takes time before you get the details and adjust your mempool. If you sit doing nothing whilst you are waiting for that to happen then you have has power going to waste. To avoid this you start work on an empty block, then if you solve it you can publish and don't risk being orphaned.
This is because the block reward is much higher than potential transaction fees. As the ratio shifts, then there is more incentive not to mine empty blocks.
How mining empty blocks affects perception, and what if any effect this has on price are not easily measured. How many blocks you would get orphaned at 25BTC a pop by waiting is measurable and directly affects bottom line.
